Geothermal Heating, Ventilating and Cooling System

ABSTRACT

An apparatus for modifying an atmosphere for use in a conditioned zone of a structure. The apparatus typically includes an underground air conduit system to take advantage of geothermal conditions to modify the temperature of air and water vapor flowing through the apparatus. A drain is typically provided for removal of water vapor that condenses to liquid in the air conduit. In some embodiments air from the conditioned zone of the structure may be recycled through the apparatus, together with a source of air that originates outside the conditioned zone of the structure. The apparatus may be integrated into other heating and cooling systems as appropriate to further control the air temperature. The apparatus may be combined with a solar heated water heater or “trombe” wall type structure where the heat generation in the winter provides a complete balance for year round stable and livable air temperatures.

CROSS REFERENCES TO RELATED APPLICATIONS

This patent application claims priority from and is related to U.S.Provisional Patent Application Ser. No. 61/085,153 filed 31 Jul. 2008,entitled: GEOTHERMAL HEATING, VENTILATING AND COOLING SYSTEM.Provisional Patent Application Ser. No. 61/085,153 is incorporated byreference in its entirety herein.

FIELD

This disclosure relates to the field of heating, ventilating and coolingsystems for buildings and structures. More particularly, this disclosurerelates to geothermal-assisted heating, ventilating and cooling systemsfor building and structures.

BACKGROUND

It is often desirable to control the temperature and/or humidity withinbuildings and outdoor structures or facilities that may be inhabited orthat may store equipment or commodities or be used for other purposes.Various heating and air conditioning systems are commercially availablefor these purposes. However, the energy costs associated with operatingsuch systems may be excessive. What is needed therefore are bettersystems and methods for economically and efficiently controlling thetemperature and/or humidity within buildings and outdoor structures orfacilities.

SUMMARY

The present disclosure provides an apparatus for modifying an atmospherefor use in a conditioned zone of a structure. One embodiment includes atank for containing a thermal ballast material for thermal transport inan underground space below a grade level. This embodiment furtherincludes an air conduit system that is disposed within the tank forcontacting the thermal ballast material. The air conduit system has anentry passage with an entry port for an air flow connection with theconditioned zone of the structure and an exit passage with an exit portfor the air flow connection with the conditioned zone of the structure.

Also disclosed is a method for forming an apparatus for modifying anatmosphere for use in a conditioned zone of a structure. The methodincludes the steps of excavating a space underground below a grade leveland casting a tank in-situ in the space. In one embodiment the methodincludes a step of disposing in the tank an air conduit system, wherethe air conduit system has an entry passage with an entry port and anexit passage with an exit port, and where the entry port and the exitport are above the grade level. The method further includes a step ofdisposing a thermal ballast material in the tank and a step of disposinga lid on the tank, where the lid covers the tank and the thermal ballastmaterial. A further step in this embodiment is backfilling tosubstantially the grade level the space underground that is not occupiedby the tank, the lid, the entry passage, and the exit passage, whileproviding for retention of the entry port and the exit port above thegrade level.

A further method is disclosed for forming an apparatus for modifying anatmosphere for use in a conditioned zone of a structure. This methodincludes the steps of excavating a space underground below a grade leveland disposing a first thermal transfer material portion in the space.This method also includes steps of disposing a tank having a bottom andsides in the space, where the bottom of the tank rests on the thermaltransfer material and disposing in the tank an air conduit system havingan entry passage with an entry port and an exit passage with an exitport, wherein the entry port and the exit port are above the gradelevel. This method further includes steps of disposing a thermal ballastmaterial in the tank and disposing a lid on the tank, where the lidcovers the tank and the thermal ballast material. The method includes astep of disposing a second thermal transfer material portion in thespace adjacent the sides of the tank, and then a step of backfilling tosubstantially the grade level the space underground that is not occupiedby the tank, the lid, the entry passage, the exit passage, and thethermal transfer material, while providing for retention of the entryport and the exit port above the grade level.

The present disclosure further provides an apparatus for modifying anatmosphere for use in a conditioned zone of a structure. Typically theapparatus includes an air conduit having a length and being disposed atleast partially in a stable temperature environment. The air conduit istypically configured with an entry port that is open to an atmospherethat is external to the conditioned zone of the structure. Other typicalconfigurations allow a combination of air from an entry port external tothe structure and recycled air from a second entry port internal to thestructure. The air conduit is also generally configured for conveying aflow of air and water vapor from the entry port, through a substantialportion of the air conduit, and out an exit port in the air conduit intothe conditioned zone of the structure. Generally the apparatus includesat least one drain that is in fluid communication with the air conduit.The at least one drain is configured to receive and expel through atleast one drain outlet a substantial portion of any water vapor thatcondenses to a liquid water as the air and the water vapor flow throughthe air conduit. Generally, the apparatus is further configured suchthat substantially all of the air and water vapor that flows through theapparatus travels a distance that is substantially equal to the lengthof the air conduit. In some embodiments the at least one drain comprisesa drainage pipe that is disposed in a substantiallycontinuously-downward-sloping orientation. In some embodiments the atleast one drain comprises a drainage pipe that is disposed in asubstantially continuously-downward-sloping orientation and the at leastone drain outlet is disposed proximal to the entry point or proximal tothe exit point of the air conduit. In some embodiments the air conduitis disposed in a substantially continuously-downward-sloping orientationfrom the exit port to the entry port and the drain comprises a troughportion of the air conduit and the entry port comprises the at least onedrain outlet. In some embodiments the air conduit is disposed in asubstantially continuously-downward-sloping orientation and the at leastone drain comprises a trough portion of the air conduit and the at leastone drain outlet comprises a drain hole in the trough portion.

A further embodiment provides a system for conditioning air in aconditioned zone of a structure that includes a source of air externalto the conditioned zone and a regulator configured to provide aregulated flow rate of external air from the source of external air.This further embodiment also generally includes an air conduit systemthat is disposed at least partially in a stable temperature environmentand that has a first entry port that is in fluid communication with theair in the conditioned zone of the structure, and that has a secondentry port that is in fluid communication with the regulated flow rateof external air, and that has an exit port into the conditioned zone ofthe structure. This further embodiment typically also provides a sourceof pressure differential that flows air into the air conduit system fromthe first entry port and from the second entry port of the air conduitsystem and through a substantial portion of the air conduit system andout of the exit port of the air conduit system into the conditioned zoneof the structure.

Another further embodiment of an apparatus for modifying an atmospherefor use in a conditioned zone of a structure provides a plurality offlow reversion blocks interconnected by hollow air conduit. Each flowreversion block has a plurality of openings in only one face, whereinair enters the block through one or more openings in the face and exitsthe block through one or more openings the face.

BRIEF DESCRIPTION OF THE DRAWINGS

Various advantages are apparent by reference to the detailed descriptionin conjunction with the figures, wherein elements are not to scale so asto more clearly show the details, wherein like reference numbersindicate like elements throughout the several views, and wherein:

FIG. 1 is a somewhat schematic perspective view of an apparatus formodifying an atmosphere for use in a conditioned zone of a structure.

FIG. 2 is a somewhat schematic perspective view of an apparatus formodifying an atmosphere for use in a conditioned zone of a structure.

FIG. 3 is a somewhat schematic top view of an apparatus for modifying anatmosphere for use in a conditioned zone of a structure.

FIG. 4 is a somewhat schematic cross section of hollow air conduit and adrainage pipe.

FIG. 5 is a somewhat schematic elevation view of an air conduit systemand a drainage pipe.

FIG. 6 is a somewhat schematic top view of a portion of an apparatus formodifying an atmosphere for use in a conditioned zone of a structure.

FIG. 7 is a somewhat schematic top view of an apparatus for modifying anatmosphere for use in a conditioned zone of a structure.

FIG. 8 is a somewhat schematic side elevation view of a system forconditioning air in a conditioned zone of a structure.

FIG. 9 is a somewhat schematic elevation view of an apparatus formodifying an atmosphere for use in a conditioned zone of a structurecombined with a solar heating system.

FIG. 10 a somewhat schematic elevation view of an apparatus formodifying an atmosphere for use in a conditioned zone of a structurecombined with a solar heating system.

FIGS. 11A and 11B are somewhat schematic elevation views of solarcollectors.

FIG. 12 is a somewhat schematic elevation of an apparatus for modifyingan atmosphere for use in a conditioned zone of a structure combined witha solar heating system.

FIG. 13 is a somewhat schematic elevation of an apparatus for modifyingan atmosphere for use in a conditioned zone of a structure.

FIG. 14 is a somewhat schematic top view of the apparatus for modifyingan atmosphere for use in a conditioned zone of a structure.

FIG. 15 is a somewhat schematic elevation view of the apparatus of FIG.14 for modifying an atmosphere for use in a conditioned zone of astructure.

FIG. 15 a somewhat schematic elevation view of an apparatus formodifying an atmosphere for use in a conditioned zone of a structurecombined with a solar heating system.

FIG. 17 is a plot of data from an apparatus for modifying an atmospherefor use in a conditioned zone of a structure that was installed for testpurposes.

FIG. 18 is a somewhat schematic elevation view of the test apparatusthat generated the data of FIG. 17.

DETAILED DESCRIPTION

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings, which form a parthereof, and within which are shown by way of illustration the practiceof specific embodiments of an apparatus for conditioning a flow of airand water vapor from an outdoor atmosphere into a structure andembodiments of an apparatus for conditioning air in a structure andembodiments of an underground air conduit system for conditioning airflowing from an outdoor atmosphere into a structure. It is to beunderstood that other embodiments may be utilized, and that structuralchanges may be made and processes may vary in other embodiments.

In most of the inhabited world it is desirable (at least during parts ofthe year) to establish an air quality within various structures that is“better” than the ambient atmospheric air quality. Desirable air qualityparameters include the following:

Appropriate temperature range

Appropriate relative humidity

Minimal inorganic or carbon particulate inclusions

Minimal organismic inclusions, such as pollen, fungicidal spores, etc.

Minimal harmful odors or chemical vapors

Minimal or no radon gas

Proper oxygenation

Structures for which these interior atmospheric parameters are desirableinclude residential, commercial and agricultural structures. Residentialstructures include both normally-occupied buildings (homes orapartments) as well as ancillary structures such as garages, atriums,and various out-buildings such as gazebos, greenhouses, and so forth.Commercial structures include offices, retail facilities, hotels,nursing homes, hospitals, airport terminals, theatres, arenas,factories, warehouses, greenhouses, and so forth. Agriculturalstructures include animal shelters, grain barns, greenhouses andancillary farm buildings. In some instances it may be desirable toenhance the air quality in only a portion of a structure. The term“conditioned zone” is used herein to refer to that portion of theinterior of a structure (which in some embodiments may be the entireinterior of the structure) that is subject to atmospheric modification.

A device is presented herein where air is brought into a structure(residential, commercial or industrial) through an underground airconduit or equivalent structure, acting as a heat exchanging system withthe underground prevailing geothermal temperature, to condition theincoming air to be of similar temperature to the prevailing geothermaltemperatures. This device may be utilized as a stand alone device orintegrated with conventional heating, ventilating, and air conditioning(HVAC) components such as heat pumps, air conditioners, and furnaces.This device can also be integrated with a solar hot water heating or“trombe” wall type system, engineered to collect heat to provide theremaining energy required to raise the temperature ranging in the wintertime from about 55° F. to about 70° F. The structure then becomessubstantially “temperature balanced” between geo and solar temperaturesources. Implication is of a temperature controlled structure withoutthe use of any fossil fuel or externally provided electric power withthe exception of a small solar cell system to operate an air fan and aliquid delivery system from the trombe wall.

Features of various embodiments described herein include the following:

The geo cooling/heating unit may be utilized on new structures or onexisting structures. In the case of new structures, the assembly can beinstalled under the structure or next to or some distance from thestructure.

One or more geo modules may be utilized on an extended structure. In thecase of an extended house, for example, one wing may be shut off whennot used. In fact the module approach is desirable to prevent the largeducting of air over a large building structure.

In the case of “external structures” such as greenhouses, atriums,garages, etc. the use of only this form of heating and cooling willsubstantially prevent building temperature extremes and keep theinternal atmosphere at all times above a range from about 45° F. (about7.2° C.) to about 55° F. (about 12.8° C.), depending upon structurequality, and below a range from about 75° F. (about 24° C.) to about 85°F. (about 29° C.) in high summer.

Air may be cycled internally from the building, through one or more“geocoils” and returned to that structure. External “make up air” may befed from the outside through the geo unit (if it is outside the desiredoperating temperature range within the structure) so that a slightpositive pressure is applied to the building. This keeps air fresh, andmakes air leak from the inside to the outside, thereby eliminatingunwanted incoming air leaks.

The geo system is typically engineered to control relative humidity by awater removal system in the geocoil or by including a humidificationdevice.

In the case of residential and commercial office space where airtemperatures are to be controlled within a narrow range, say from about70° F. (about 21° C.) to about 72° F. (about 22° C.) then the air intakefrom the geocoil unit may be fed into the return air or air intake of anadditional heat pump or equivalent system, either air cooled orgeothermal heat pump, which then has only to heat air from an inlet airtemperature ranging from about 55° F. (about 12.8° C.) to about 70° F.(about 21° C.) in the winter as opposed to heating outside air, whichmay range from about −10° F. (about −23° C.) to about 30° F. (about −1°C.) depending on local conditions. In the summer time, it may be that anintegrated HVAC system has only to reduce air inlet from a temperatureof about 74° F. (about 23° C.) to about 70° F. (about 21° C.) as opposedto dealing with air entering the building at about 100° F. (about 37°C.) from air leaks into the building. (The air leaks into the buildingmay be substantially eliminated by slightly over-pressurizing theinterior of the building.)

From the point above, the geo air intake may be combined with a sunheated hot water system and heat exchanged to be used as a means toraise the inlet air from about 55° F. (about 12.8° C.) to about 70° F.(about 21° C.) in winter times as opposed to utilizing a heat pumpsystem of any type.

Plastic conduits may be used to provide cleanable surfaces for thereduction of mold, spores etc. This generally provides a thermalinsulation between ground temperature and the air inside geo airconduits. The use of carbon nanotube doped plastics for the fabricationof high thermal conductivity piping may enhance the apparatusperformance. For example, the use of plastic air conduits with carbonnanotube impregnation (to improve the thermal conductivity of the airconduit walls) may be used to provide a cleanable air conduit systemthat has greatly enhanced heat transfer from the soil to the air insidethe geo air conduit. The use of internal hydrophobic materials asinternal coatings, or other coatings may be used to repel water andcontaminant collection on internal surfaces of piping and materials incontact with the air brought into a structure

Air conduits are typically specially sealed to prevent radon or othermaterials being transferred from the soil to the air inside the airconduit.

The internal air conduit walls may be plastic, optionally including thenanotube impregnation and/or may be coated with hydrophobic surfactants(designed to prevent adherence of water droplets and contaminants to theinternal air conduit walls) to permit enhanced transport of condensedwater vapor and other materials to the geo system drain lines.

The geo air conduit system may be embedded in raw soil, or in sand, orin water, or in other subterranean materials, to allow “conduitshuffling” if temperature shifts occur in the air conduit for anyreason. The air conduits may also be embedded in concrete to allow highthermal contact from the air conduit wall to the surrounding soilthermal profile.

Where systems are embedded in a hillside then water and condensatedrainage may be arranged without special needs for the drain sumpdiscussed elsewhere herein. Where the system is built on flat or nearflat ground so that the elevation of the desired temperature profile isbelow grade, then the drain sump as mentioned in this application istypically provided. In addition the system is preferably substantiallywater and air tight to prevent water build up in the event of floodingor locations where the water line might be below grade but above theelevation of the geo system air conduit.

Various embodiments of an apparatus for modifying an atmosphere for usein a conditioned zone of a structure may be combined with a solarheating system and consequently provide a source of heat and a source ofcooling that may be totally independent of any fuel system. If solarcells are utilized to provide a source of power (when combined with abattery and appropriate controls system) for controllers and foroperation of pumping of air and fluid, then the system may be completelyfree of any external source of energy from conventional sources(electricity, fossil, nuclear, oil). Such systems may also be configuredto provide hot water as necessary.

Various other heating and cooling systems may be used in cooperationwith embodiments described herein to modify the atmosphere in theconditioned zone of a structure. Examples are furnaces, air conditioningunits, and heat pumps. Some heat pumps may take advantage of ageothermal effect to improve their efficiency. This geothermal effect isa condition where the temperature of the earth underground is differentand more stable than the atmospheric temperature at that locale. Forexample, in the southern United States, the ground temperature at aboutsix feet (approximately 2 meters) below the surface of the earth remainsat temperatures between about 50° F. to 55° F. (about 10° C. to 13° C.)year around, whereas the atmospheric temperature may range from betweenabout 10° F. to 100° F. (about 12° C. to 38° C.). A similar geothermaleffect occurs in lakes and streams although currents may modify layersof differing temperature. These geothermal effects may, for example, beused by heat pumps to remove or add heat in order to heat or coolconditioned zones of various structures. The process typically involvespumping water or other thermal ballast material through a conduit thathas been configured to establish the temperature of the liquid close tothe underground temperature. Typically the heat pump extracts heat fromthe liquid when the atmospheric temperature is lower than the groundtemperature and transfers heat into the liquid when the atmospherictemperature is higher than the ground temperature.

Disclosed herein are various embodiments of apparatuses for passing airthrough an underground air conduit system in order to heat or cool theair that flows through the air conduit system. Almost always, such flowincludes both air and water vapor. For example, atmospheric air almostnever has zero percent humidity; there is almost always some water vaporin atmospheric air. The term “air conduit” as used herein refers to aconduit for conveying air and water vapor. If the air and water vaporenter the air conduit system at a temperature that is higher than theunderground temperature a portion of the water vapor may occasionallycondense into liquid water. It is desirable to remove the condensatewater from the air conduit system so that the water does not plug up theair conduit system or create other problems such as excessively highrelative humidity levels.

FIG. 1 illustrates an apparatus 10 for modifying an atmosphere for usein a conditioned zone 12 of a structure. The apparatus 10 includes anair conduit system 14. The air conduit system 14 is an example of ageocoil that was referred to previously herein. The air conduit system14 includes six segments of conduit material such as piping or conduit,A, B, C, D, E, F, and an optional seventh segment, G. Other embodimentsmay include more or fewer segments. The air conduit system 14 isconfigured to flow the atmosphere through a serpentine path, which isbeneficial for minimizing the footprint required for such an apparatus.As used herein the term “serpentine path” refers to a path that startsas pointed in a first direction and then bends to a second directionthat is substantially reverse to the first direction and then bends to athird direction that is substantially reverse to the second directionand pointed in substantially the same direction as the first direction.This pattern may be repeated multiple times in whole or in part. The airconduit system 14 may be formed from a plastic material such aspolyvinylchloride (PVC), or high density polyethylene (HDPE), orpolyethylene, or from other plastic materials. The air conduit system 14may be formed from plumbing pipes or drainage culverts or tubing orsimilar products. It is desirable that the materials used forconstruction of the air conduit system 14 have minimal out-gassingcharacteristics. The air conduit system 14 is disposed at leastpartially underground, or disposed in another environment having agenerally stable temperature. As used herein the term “underground”refers to a location that is in the earth (below grade level). Someembodiments include configurations where the air conduit system 14 is atleast partially disposed underwater. “Underwater” refers to a locationthat is in a body of water such as in a lake or river, or that isunderground below the water table. In some embodiments portions of theair conduit system 14 may be underground and portions may be underwater.The air conduit system 14 has an entry port 16 that is in fluidcommunication with an atmosphere 18 that is external to the conditionedzone 12 of the structure. As used herein the term “in fluidcommunication” means that a fluid may pass between the recited elements(in this case the source atmosphere 18 and the entry port 16) eitherdirectly or may pass between the recited elements through moreintervening elements. Typically the source atmosphere 18 is the outdoorambient atmosphere but in some embodiments the source atmosphere may beanother source of air, either natural or man-made. For example, in someembodiments optional segment G may be included and the source atmosphere18 may be from the conditioned zone 12 of the structure. Inconfigurations that include the optional segment G, the entry port 16 isthe opening of the optional segment G.

The air conduit system 14 also has an exit port 20 that is in fluidcommunication with the conditioned zone 12 of the structure. The airconduit system 14 is configured for conveying a flow of air and(typically) water vapor from the source atmosphere 18, into and throughthe entry port 16, through a substantial portion of the air conduitsystem 14, and out the exit port 20 into the conditioned zone 12 of thestructure.

In the embodiment of FIG. 1, the lateral segments B, C, D, E, and F ofthe air conduit system 14 are disposed substantially parallel to a flatplane 22 that is geologically level. (“Geologically level” refers tobeing horizontal with respect to the earth.) In such configurations theair conduit system (e.g., air conduit system 14) is referred to as beingdisposed substantially level. If the air contains water vapor, as theair and water vapor are drawn through the air conduit system 14 and arecooled below the dew point of the air/vapor mixture, a portion of thewater vapor may condense. Because the air conduit system 14 issubstantially level, any water vapor condensation might remain insidethe air conduit system for an extended period of time. Such residualwater might provide an environment for undesirable organisms such asmold to live and grow or might develop a foul smell that might betransferred into the conditioned zone 12 of the structure. To reducethis risk, a drainage pipe 30 is provided to remove water vaporcondensate from the system 14. The drainage pipe 30 is in fluidcommunication with the air conduit system 14 through a series of standpipes 32, and water condensate is expelled through a drain outlet 34.Preferably such water condensate is expelled to the outdoor atmosphere.The term “expelled to the outdoor atmosphere” means that the watercondensate is discharged outdoors (as a liquid) at or above ground asreferenced to the localized grade level at the location of discharge.While condensation may not be a problem in many installations of the airconduit system 14, it is generally desirable to provide for discharge ofany condensation that may develop.

The drainage pipe 30 is disposed in a substantially-downward slopingorientation from a first standpipe 36 that is proximal to the exit port20 to a last standpipe 38 that is proximal to the drain outlet 34. Sincethe air conduit system 14 is substantially level, the stand pipesincrease in length from the first standpipe 36 to the last standpipe 38in order to establish the continuously-downward-sloping orientation ofthe drainage pipe 30. If the air conduit system 14 is deployed onsubstantially level ground then the moisture may be routed from thedrain outlet 34 to a sump pump for extraction from underground. If theair conduit system 14 is deployed on sloping terrain the layout of theair conduit system 14 may be configured to expose the drain outlet 34 toopen air at a location on the sloping terrain, such that the moisturedrains gravitationally from the system 14 without any pumping.

While in the embodiment of FIG. 1 the drainage pipe 30 is in asubstantially continuously-downward-sloping orientation from the exitport 20 to the entry port 16 of the air conduit system 14, in analternate embodiment the drainage pipe 30 may be in a substantiallycontinuously-downward-sloping orientation in the opposite direction(i.e., from the entry port 16 to the exit port 20). In suchconfigurations the longest (first) standpipe 36 is proximal to the entryport 16 and the shortest (last) standpipe 38 is proximal to the exitport 20 and the drain outlet 34 is proximal to the exit port 20.

In embodiments where the drain includes a drainage pipe (such asdrainage pipe 30) that is disposed in a substantiallycontinuously-downward-sloping orientation, it is advantageous to disposethe drain outlet 34 either proximal to the entry port 16 (as depicted inFIG. 1) or (where the drainage pipe slopes in the other direction)proximal to the exit port (e.g., exit port 20) of the air conduit system14. This facilitates maintenance and cleaning of the drainage pipe 30.

The normal flow of air and (typically) water vapor through the airconduit system 14 is through segments G through A. However, the drainagepipe 30 may be a potential alternate flow path. In order to ensureproper cooling or heating of air for the conditioned zone 12 of thestructure, is desirable that the apparatus 10 be configured such thatsubstantially all of the air and water vapor that flows through the airconduit system 14 travels a distance that is substantially equal to thelength of the air conduit system 14. The apparatus 10 of FIG. 1 meetsthis objective because, if some air and water vapor enters the drainoutlet 34, then air and water vapor will flow either up into the airconduit system 14 or will flow on a path through the drainage pipe 30that is substantially equal to the length of the air conduit system 14.There is no “shortcut” that would allow any significant amount of theair and water vapor flowing through the system 10 to not be exposed tothe underground temperature for a distance that is substantially equalto the distance of exposure of the air and water vapor that flowsthrough the air conduit system 14. However, in the previously-describedalternate embodiment where the drainage pipe 30 is in a substantiallycontinuously-downward-sloping orientation from the entry port 16 to theexit port 20 and the shortest (last) standpipe 38 is proximal to theexit port 20, outside air may drawn into the drain outlet 34 through thestandpipe into section A of the air conduit system 14 without travelinga distance that is substantially equal to the length of the air conduitsystem 14.

As previously indicated, in the embodiment of FIG. 1 the air conduitsystem 14 is substantially level. In an alternate embodiment the airconduit system 14 may be disposed in a substantiallycontinuously-downward-sloping orientation that parallels thesubstantially continuously-downward-sloping orientation of the drainagepipe 30. In such alternate embodiments the stand pipes 32 would all besubstantially the same length. In some alternate embodiments the airconduit system 14 may be disposed in a continuously-upward-slopingorientation from the exit port 20 to the entry port 16, and in somealternate embodiments the air conduit system 14 may be disposed withvarious segments (e.g., B, C, D, E, and F) disposed in generallyrandomly-sloping orientations. In such alternate embodiments the lengthsof the stand pipes 32 are adjusted so that the drainage pipe 30 remainsin a substantially continuously-downward-sloping orientation.

FIG. 2 illustrates a further embodiment of an apparatus 40 for modifyingan atmosphere for use in a conditioned zone 12 of a structure. Theapparatus 40 includes an air conduit system 44 comprising six segments,A′, B′, C′, D′, E′, and F′. An optional segment G′ may also be included.In other embodiments more or fewer segments may be employed. The airconduit system 44 is an example of a geocoil that was referred topreviously herein. The air conduit system 44 may be formed from aplastic material such as polyvinylchloride (PVC), or high densitypolyethylene (HDPE), or polyethylene, or other materials as discussedwith respect to the previously-describe air conduit system 14. The airconduit system 44 is disposed at least partially underground orunderwater or in another environment having a stable temperatureenvironment. The air conduit system 44 has an entry port 46 that is influid communication with a source atmosphere 18. As explained withrespect to FIG. 1, the optional segment G′ may be included to utilizeair from the conditioned zone 12 of the structure as the sourceatmosphere 18. The air conduit system 44 also has an exit port 50 thatis in fluid communication with the conditioned zone 12 of the structure.The air conduit system 44 is configured for conveying a flow of air and(typically) water vapor from the source atmosphere 18, in through theentry port 46 and through a substantial portion of the air conduitsystem 44, and out the exit port 50 into the conditioned zone 12 of thestructure. If the optional segment G′ is used, the entry port 46 is theopening of the optional segment G′.

The lateral segments B′, C′, D′, E′, and F′ of the air conduit system 44of FIG. 2 are disposed in a substantially continuously-downward-slopingorientation with respect to the horizontal flat plane 22. In suchconfigurations the air conduit system (e.g., air conduit system 44) isreferred to as having a substantially continuously-downward-slopingorientation.

A trough portion 60 of the air conduit system 44 forms a drain for theapparatus 40. Water 62 may condense into the trough portion 60 and flowout of the air conduit system through the entry port 46, and in suchembodiments the entry port 46 comprises the drain outlet. In someembodiments at least one drain hole 64 may be provided in the troughportion 60 of the air conduit system 44 to permit some of the water 62to be expelled from the air conduit system 44 before the water 62reaches the entry port 46. If the optional segment G′ is included in theapparatus 40, then a drain hole 64 is typically provided proximal to theintersection of segments F′ and G′. If the air conduit system 44 doesnot include any drain hole(s) 64 (i.e., all of the condensate water 62drains out the entry port (46)), then typically the air conduit system44 is deployed on a sloping terrain and the air conduit system 44 isconfigured to expose the entry port 46 to open air at a location on thesloping terrain where the moisture may drain.

If the drain hole 64 is underground and not in fluid communication withthe source atmosphere 18 or in fluid communication with any other sourceof air and water vapor, such an embodiments may be configured such thatsubstantially all of the air and water vapor that flows through the airconduit system 44 travels a distance that is substantially equal to thelength of the air conduit system 44. That is, substantially all of theair and water vapor that flows through the air conduit system 44 entersthe air conduit system through the entry port 46, and exits through theexit port 50.

In the embodiment of FIG. 2 the air conduit system 44 is in asubstantially continuously-downward-sloping orientation from theintersection of segments A′ and B′ to the unconnected end of segment F′(if the optional segment G′ is not included) or to the intersection ofsegments F′ and G′ (if the optional segment G′ is included). In analternate embodiment the air conduit system 44 may be in a substantiallycontinuously-downward-sloping orientation in the opposite direction.That is, the air conduit system may be in substantiallycontinuously-downward-sloping orientations from the unconnected end ofsegment F′ (if the optional segment G′ is not included) or from theintersection of segments F′ and G′ (if the optional segment G′ isincluded) to the intersection of segments A′ and B′. In suchconfigurations a drain hole (such as drain hole 64) is typicallyprovided proximal to the intersection of segments A′ and B′. In someembodiments the air conduit system 44 is disposed substantially parallelto the flat plane 22. In such configurations a plurality of drain holessimilar to the drain hole 64 are typically employed to drain thecondensate water 62 from the air conduit system 44.

FIG. 3 depicts an embodiment of an underground apparatus 100 formodifying an atmosphere for use in a conditioned zone of a structure.The apparatus 100 is an example of a geocoil that was referred topreviously herein. The apparatus 100 includes a plurality of flowreversion blocks 102 that are interconnected by hollow air conduit 104.The reversion blocks 102 are used to direct the flow of air and watervapor from a source atmosphere in a serpentine path. The reversionblocks 102 may be constructed of metal, cast concrete, mold-formedplastic or similar construction and materials. Preferably any concretesurfaces are lined with a barrier to prevent incursion by radon or otherunderground gases. The hollow air conduit 104 may be a plastic materialsuch as polyvinylchloride (PVC) or high density polyethylene (HDPE), orpolyethylene, or other materials, as previously described. The hollowair conduit 104 may be formed from plumbing pipes or drainage culvertsor tubing or similar products fabricated from other materials. Each ofthe reversion blocks 102 have a plurality of faces 106, and each of thereversion blocks 102 have a plurality of openings 108 in only one face(e.g., face 110). A plurality of U-channels 112 are provided in each ofthe reversion blocks 102, and the reversion blocks 102, the air conduit104, and the U-channels 112 are configured such that air enters thereversion block 102 through one or more openings 108 in the single face(e.g., 110) and exits the reversion block 102 through one or moreopenings 108 in the single face (e.g., 110). The apparatus 100 has anentry port 114 and an exit port 116. The reversion blocks are typicallydisposed underground and may be configured so that the hollow airconduit 104 has a substantially continuously-downward-slopingorientation from the exit port 116 to the entry port 114.

Note that the U-channels 112 may be passages cast into the reversionblocks 102, or the U-channels 112 may comprise plastic tubes wherein thereversion blocks 102 are cast around the plastic tubes. In someembodiments the U-channels 112 comprise plastic tubes with no concretecast there-around (i.e., no reversion block 102 is employed). In eitherembodiment one or more drainage pipes 118 may be used to providemoisture drainage. If more than one drainage pipes 118 are employed,drainage may occur through one or more of the drainage pipes 118,depending on how the moisture is routed. If the apparatus 100 isdeployed on substantially level ground then the moisture may be routedto a sump pump for extraction from underground. If the apparatus 100 isdeployed on sloping terrain the layout of the apparatus 100 may beconfigured to expose the drain end of the drain pipe(s) 118 to open airat a location on the sloping terrain, wherein the moisture drainsgravitationally from the system without any pumping.

FIG. 4 illustrates a cross section of a portion of the apparatus 100 ofFIG. 3. It is preferable that a diameter 120 of the drain pipe 118 besignificantly smaller than a diameter 122 of the hollow air conduit 104so that very little air flows through the drain pipe 118 compared withthe amount of air flowing through the hollow air conduit 104. Even ifthe length of the drain pipe 118 is less than the length of the hollowair conduit 104, substantially all of the air and water vapor that flowsthrough the apparatus 100 may travel a distance that is substantiallyequal to the length of the hollow air conduit 104 if the diameter 120 ofthe drain pipe 118 significantly smaller than the diameter 122 of thehollow air conduit 104, because in that configuration of diameters verylittle air and water vapor may flow through the drain pipe 118 comparedwith the amount of air and water vapor that flows through the hollow airconduit 104.

FIG. 5 illustrates an elevation view of a portion of the apparatus 100of FIG. 3. Direction arrow 130 represents the direction of air flowthrough the hollow air conduit 104 and direction arrow 132 representsthe direction of water condensate flow through the hollow air conduit104 into the drain pipe 118. In deployments of air conduits ingeographic areas where flooding may occur or the air conduit is exposedto the underground water table, it is highly desirable that the airconduit system and the drainage pipe (if used) be water tight andconfigured to drain any flood water or underground water from thesystem.

FIG. 6 illustrates an alternate embodiment of a reversion block 170. Thereversion block 170 includes a hollow block 172. The hollow block 172has two ports 174 into a hollow interior 176. Conduit tubes 178 aredisposed in the ports 174 of the reversion block 170. Caulking or asimilar material may be used to seal the conduit tubes 178 in the ports174. Alternately, since the reversion block 170 is typically disposedunderground, dirt or other material such as concrete may be packedaround the outside of the interfaces between the ports 174 and theconduit tubes 178 to seal the conduit tubes 178 in the ports 174. Adrain hole 180 may be provided in the bottom of the hollow block 172. Insome embodiments the reversion block 170 may be constructed with nobottom face, and in such embodiments the entire open bottom is the drainhole.

FIG. 7 depicts a top view of an alternate configuration of anunderground apparatus 190 for modifying an atmosphere for use in aconditioned zone of a structure. Apparatus 190 employs a series of airconduits 192 disposed alternately over and under a series of reversionblocks 194.

FIG. 8 depicts an apparatus 200 for conditioning air in a conditionedzone 202 of a structure. The apparatus 200 includes an underground airconduit system 204. A drain 206 is provided for the underground airconduit system 204 to remove a substantial portion of any water vaporcondensation that may form in the air conduit system 204. The airconduit system 204 has a first entry port 210 that is in fluidcommunication with a first source of air 212 that is in the conditionedzone 202. Consequently, in the embodiment of FIG. 8 air from thestructure may be recycled through the apparatus 200. There is aregulator 216 that is configured to provide a regulated flow 218 ofexternal air 220. The regulator 216 may also be configured to regulatethe flow of the first source of air 212. The terms “regulated flow” and“regulate the flow” as used herein refer to configurations where a flowrate is adjusted depending upon the condition of at least one flowcontrol parameter. For example, the regulator 216 may be a back pressurecontrol valve that is set to maintain a flow rate that is adjusted tomaintain a slight overpressure between the air pressure in theconditioned zone 202 and the outside air pressure 226. A binary flowrate (“on” or “off”) is considered to be an “adjusted” flow rate. Notethat in the embodiment of FIG. 8 the external air 220 is outdoor ambientair, but in other embodiments the external air 220 may be from adifferent natural or man-made air source.

The air conduit system 204 has a second port 224 that is in fluidcommunication with the regulated flow 218 of external air 220. The airconduit system 204 also has an exit port 230 into the conditioned zone202. In the embodiment of FIG. 8 an air processor 240 is provided toinduce a flow of air into the air conduit system 204 from the firstentry port 210 and from the second entry port 224 through the airconduit system 204 and out of the exit port 230 into the conditionedzone 202. The air processor 240 may also be configured to shut off airflow from the air conduit system 204 when such air flow would not bebeneficial to maintaining a desired temperature inside the conditionedzone 202. The air processor 240 may be suction fan. The air processor240 is an example of a source of pressure differential. In otherembodiments the source of a pressure differential may be a passivethermal convection arrangement or the source of pressure differentialmay be the fan of a heating furnace. A fan is the preferred source ofpressure differential to establish a slight overpressure within theconditioned zone compared to outside air pressure. If the source ofpressure differential is the fan of a heating furnace, the furnace maybe configured to draw a second source of air 242 from the conditionedzone 202 into the furnace.

As further illustrated in FIG. 8, a first source of air 212 from theconditioned zone 202 may be drawn through the first entry port 210 intothe air conduit system 204. This flow is typically induced by the airprocessor 240, which as previously stated may be a fan or a furnace fanassembly. A manifold portion of the regulator 216 and an air filter maybe provided to facilitate mixing and cleaning of air from the firstsource of air 212 from the conditioned zone 202 and the external air220. Note—when the outside air temperature 250 is cold (for examplebelow 50° F. (10° C.), the regulator 216 is typically configured to shutoff air from the first source of air 212 and only external air 220 isdrawn through the air conduit system 204 where it may be warmed up to50° F. (10° C.).

The air processor 240 preferably includes a valve manifold that canselectively draw air from either the air conduit system 204 or from thesecond source of air 242 from the conditioned zone 202, or from both ofthose sources, depending upon the temperature 252 inside the conditionedzone 202 and the outside air temperature 250. One or more appropriatelyplaced thermostats may be used to make a single or collective decisionregarding the air sources.

In some embodiments a thermostat controls a variable speed fan whichcontrols air intake through the air conduit system 204 and out the exitport 230. If the temperature 252 in the conditioned zone 202 increasesabove a set point, then the fan speed may be increased to introduce morecooling. In some embodiments the apparatus 200 may be configured foroptionally stopping the flow of the first source of air 212, and in suchconfiguration, if the temperature 252 in the conditioned zone dropsbelow a set point then the flow of the first source of air 212 may bestopped and external air 220 may be the only flow of air through the airconduit system 204. If necessary, external air 220 (and optionally airfrom the first source of air 212) and/or the second source of air 242from the conditioned zone 202 may be heated (such as by a furnaceportion of the air processor 240) to reach a target temperature.

Typically it is desirable to maintain a temperature 252 inside theconditioned zone 202 of about 70° F. (about 10° C.). As previouslyindicated, the underground temperature 254 is typically around 50° F.(about 10° C.). When the outside air temperature 250 is hot, e.g., about90° F. (about 32° C.) or at least above about 70° F. (about 21° C.) theregulator 216 may be continuously turned on and, depending upon thebuilding size and occupancy, a small, e.g., about 20 cubic feet perminute (about 0.56 m³/min), volume of external air 220 may drawn throughthe regulator 216. This air is added to the first source of air 212 fromthe conditioned zone 202. That is, the air processor 240 typically drawsair from the external air 220 and air from first source of air 212 thatis in the conditioned zone 202 into the air conduit system 204 to becooled.

If the outside air temperature 250 is between about 50° F. and 70° F.(about 10° C.-21° C.) then air flow from the air conduit system 204 maybe shut off and if the air processor 240 is a furnace, a second sourceof air 242 from the conditioned zone may be drawn into the furnace asappropriate under (for example) thermostat control.

When the outside air temperature is cold, e.g., below about 50° F.(about 10° C.), the air processor 240 is configured to shut off air fromthe air conduit system 204 and air from the second source 242 in theconditioned zone 202 is preferably drawn through a heater in the airprocessor 240 to heat the conditioned zone. Alternately, when theoutside air temperature 250 is cold, e.g., below about 50° F. (about 10°C.) then the regulator 216 may configured to shut off the first flow ofair 212 from the conditioned zone 202 and flow of external air 220 maybe continuously turned on and, depending upon the building size andoccupancy, a small, e.g., about 20 cubic feet per minute (about 0.56m³/min), volume of external air 220 may drawn through the regulator 216.The air processor 240 draws the external air 220 into the air conduitsystem 204 to be warmed to a temperature approaching 50° F. (about 10°C.) prior to heating that air in a furnace portion of the air processor240.

The underground air conduit system 204 may comprise relatively largediameter pipes—such as about 3 to 4 inches (about 7.6 to 10 cm) indiameter or larger. The specific diameter of the pipes is preferablyselected in view of site geothermal conditions, the linear footage ofpipe that will be used, and the particular requirements of thestructure/building with which it will be used.

The pipes (e.g., tubes 104 of FIG. 3) are preferably constructed ofplastic with the following characteristics:

-   -   good thermal conductivity to permit effective heat transfer    -   low porosity to prevent infusion of radon or other underground        gas transference    -   chemical resistance to mold build up    -   easy clean-ability    -   sloped orientation for drainage, and    -   condensate drainage and removal system    -   low out-gassing of vapors from the plastic itself

Various embodiments described herein are designed to utilizecomparatively stable sub-surface temperatures to condition air suitablefor occupied structures. At approximately 6 ft (about 2 m) below groundlevel the ambient temperature is approximately 50° F. to 55° F. (about10° C. to about 13° C.) year round in the southern USA. Such a locationwhere variation in temperature is substantially less than the variationin ambient atmosphere temperature is referred to as a stable temperatureenvironment. If sufficient length and surface area of air conduit is setat that level, then heat transfer through the air conduit structure willcause air passing through the air conduit to substantially adjust to theambient soil temperature. Further air quality adjustments may includechanges in relative humidity and removal of spores and other particulatematerials. Additionally, the introduction of unacceptable chemicallybased vapors may be prevented or controlled to provide good quality airfor long term good living conditions.

Preferably the air conduit systems are configured so that the internalsurfaces are smooth and resist the buildup of moisture, dirt, mold orother contaminants that may be detrimental to the quality of the air inthe piping. Preferably the piping is configured so that “duct cleaning”approaches can be utilized to clean and maintain the air conduit systemover the long term.

Various embodiments described herein work best when configured tosupport a specific structure. Sprawling complexes of buildings mayadvantageously utilize several of these systems, where sections ofbuildings that are not in current use may be closed off. However,because the cost of operation of these systems is typically so low thattheir operation may be maintained to economically maintain an enclosedarea in clean and good condition until occupied and then one or moreconditioned zones may be easily brought to optimal operatingtemperature. Supplemental systems may be utilized to provide temperaturestabilization of walls and roofing structures to minimizeheating/cooling requirements for building envelopes. Primary andsupplemental systems may be used independently or together.

Embodiments described herein may be integrated into new structures, orretrofitted into existing structures. Underground air conduit systemsmay be placed under the building or in an adjacent area. Systems may beapplied to permanent home structures and also mobile home andmanufactured structures by placing the structure over a pre buriedgeothermal system.

One of the primary benefits of embodiments described herein is that theuse of geothermal temperatures minimizes the energy consumption requiredto keep a home or other structure in comfortable conditions,irrespective of external weather conditions. Systems described hereininvolve simple elements that minimize system installation andmaintenance costs compared with Freon-based air conditioning systems,heat pumps, and similar electro-mechanical approaches. For example,systems may be designed that, at the most, utilize a fan and typicallyhave no other moving parts. Therefore, the expected lifetime of thesesystems may be expected to equal or exceed the lifetime of theassociated structure. Since no internal heat exchangers or otherexpansive equipment is required, the equipment “footprint” is minimal,which maximizes available living space.

FIG. 9 depicts a geo cooling system 300 for modifying an atmosphere foruse in a conditioned zone 302 of a structure 304. Also depicted is anexternal system 320 for heating hot water (or a thermal mass) and asystem 322 for transferring heat to a heat storage system 330. Furtherthere is a system 332 for transferring heat to a radiator/heat exchanger334 through which inlet air 336 from the geo cooling system is fed intothe conditioned zone 302. Hot water 340 may also be provided from theheat storage system 330.

FIG. 10 depicts an alternate configuration of the elements of FIG. 9.For example, in the embodiment of FIG. 10 the heat storage system 330 isabove ground system 322 for transferring heat to a heat storage systemand unlike the embodiment of FIG. 9, in the embodiment of FIG. 10 thereis no provision for hot water 340 Also the embodiment of FIG. 10provides for the admittance of outside air 344 into the conditioned zone302 of the structure 304.

FIGS. 11A and 11B are somewhat schematic illustrations of solarcollectors that may be used as components of the external system 320 forheating hot water (or a thermal mass).

FIG. 12 depicts a geo cooling system 300 for modifying an atmosphere foruse in a conditioned zone 302 of a structure 304. Also depicted is anexternal system 320 for heating hot water (or a thermal mass) and asystem 322 for transferring heat to a liquid heat exchanger 370. Furtherthere is a system 374 for transferring heat to a radiator/heat exchanger378 through which inlet air 336 from the geo cooling system is fed intothe conditioned zone 302.

FIG. 13 depicts a further apparatus 400 for modifying an atmosphere foruse in a conditioned zone of a structure. The apparatus 400 has a tank404 for containing a thermal ballast material 408 in an undergroundspace 412 in the ground 414 below a grade level 416. The grade level 416may generally conform to the topography of the surrounding region, orthe grade level 416 may be modified for such purposes as enhancingdrainage. The tank 404 may be constructed from concrete, metal,fiberglass, plastic, or other materials. Typically the thermal ballastmaterial 408 comprises water. Other liquids may be used or included withwater to improve the thermal conductivity or other properties of thethermal ballast material 408. Gel-like semi-solid materials such assilicone thermal transfer materials, greases, or gummy materials thathave relatively high thermal conductivity may also be used as thethermal ballast material 408.

In the embodiment of FIG. 13 there is an air conduit system 420 disposedwithin the tank 404 for contacting the thermal ballast material 408. Theuse of a tank 404 with a thermal ballast material 408 may improvethermal connectivity between the ground 414 and the air conduit system408 compared with placing the air conduit system 408 directly in theground 414. The thermal ballast material 408 generally enhances heattransfer between the tank 404 and the air conduit system 420. The airconduit system 420 has an entry passage 424 with an entry port 428 foran air flow connection 432 with the conditioned zone of the structure(such as conditioned zone 12 of FIG. 1) or with outside air 434, and anexit passage 436 with an exit port 440 for an air flow connection 444with the conditioned zone of the structure (such as conditioned zone 12of FIG. 1). Air flow into the air conduit system 420 is indicated by afirst arrow 448 and air flow out of the air conduit system 420 isindicated by a second arrow 452. The air conduit system 420 includes aseries of conduits 472 each of which has one end 476 disposed in a firstmanifold box 480 and a second opposing end 484 disposed in a secondmanifold box 488. If only one conduit 472 is used there may be no needfor the first manifold box 480 or the second manifold box 488. A singleconduit 472 may connect directly to the entry passage 424 and the exitpassage 436. The conduits 472 are in contact with the thermal ballastmaterial 408. The first manifold box 480 is in fluid communication withthe entry passage 424 and the second manifold box 488 is in fluidcommunication with exit passage 436, such that input air 492 may flowinto the entry port 428, then into the first manifold box 488, then intothe conduits 472 then into the second manifold box 488, then into theexit passage 438 and finally out the exit port 440 as output air 496.

While the input air 492 is flowing through the conduits 472, heat istransferred from the thermal ballast material 408 through the conduits472 to the input air 492 if there is a falling temperature gradient fromthe thermal ballast material 408 through the conduits 472 to the inputair 492, and heat is transferred from the input air 492 through theconduits 472 to the thermal ballast material 408 if there is a fallingtemperature gradient from the input air 492 through the conduits 472 tothe thermal ballast material 408.

In the embodiment of FIG. 13 there is a lid 500 that covers the tank 408and there is foam material 504 that is disposed above the lid 408 in theunderground space 412 below the grade level 416. The foam material 504helps maintain the thermal stability of the thermal ballast material 408in the tank 404. A thermal transfer material 508 is disposed under thetank 404 and around the sides of the tank 404. The thermal transfermaterial 508 is typically installed as a slurry (such as raw concrete)or a sludge (such as mud), and is provided for the purpose of enhancingthe thermal conductivity between the tank 404 and the underground space412. In time the thermal transfer material 508 may solidify from itsinitially-installed slurry or sludge consistency, but in doing so it isexpected to maintain some measure of enhanced thermal conductivity,particular in comparison with voids (air pockets) that might occurwithout the installation of the thermal transfer material 508.

FIG. 14 illustrates a top view of an apparatus 600 for modifying anatmosphere for use in a conditioned zone of a structure. The apparatus600 includes an air conduit system 604 that includes a set of conduits608 having a serpentine path. In some embodiments the set of conduits608 is a single conduit, and in some embodiments the set of conduits 608includes a plurality of conduits that are disposed one atop another. Byvirtue of the orthographic projection used for this illustration, thetop-down view of FIG. 14 is the same regardless of whether the set ofconduits 608 is one conduit or a plurality of conduits that are disposedone atop another. Each conduit in the set of conduits 608 is preferablyformed as an extrusion process that forms a straight segment and thenforms a “u-bend” and then forms another straight segment and then formsanother “u-bend,” and so forth. Alternately the set of conduits 608 maybe formed by bending straight tubes into a serpentine path usingmechanical tube benders, optionally with heating of the straight tubes.Such forming processes may produce geometries that have a substantiallycontinuously-downward-sloping orientation, which simplifies installationof the set of conduits 608 in the field.

In the embodiment of FIG. 14 the set of conduits 608 is disposed withina tank 612 and a thermal ballast material 616 is disposed in the tank612. In some embodiments the set of conduits 608 may be disposedunderground directly in contact with soil. The set of conduits 608connects to a first manifold box 620 and a second manifold box 624. Thefirst manifold box 620 includes a primary entry port 628 and a secondaryentry port 632. Typically only one of the two entry ports (628 or 632)is employed in a particular installation, with the other port beingclosed off. Alternative ports (e.g., 628 and 632) may be provided inorder to facilitate different installation options. The second manifoldbox 624 also has a primary exit port 636 and a secondary exit port 640.The tank 612 typically has a length 644 of about 12 feet (about 3.7meters) and a width 648 of about 8 feet (about 2.4 meters).

FIG. 15 illustrates a side view of the apparatus 600 of FIG. 14. Forsimplicity of illustration, FIG. 15 illustrates only one conduit in theconduit set 608. As previously discussed, the conduit set 608 mayinclude multiple conduits set one atop another which, if illustrated,would be visible in FIG. 15 in a manner analogous to strands ofinsulated conductors in a ribbon cable unfurling back and forth acrossthe illustration from side to side and top to bottom, except that themultiple conduits (such as in conduit set 608) are typically spacedapart, whereas the strands of insulated conductors in a ribbon cableadjoin each other. The use of multiple smaller pipes instead of a singlelarger pipe increases the surface area of pipe that is exposed to thethermal ballast material 408. For example, one six inch diameter conduithas an equivalent cross section of four three inch diameter conduits andtwice the surface area of the six inch conduit.

The tank 612 typically has a height 652 of about 3 feet (about 0.9meters). FIG. 15 further illustrates that the conduit set 608 isdisposed in a tilted orientation such that any condensation of watervapor in air flowing through the conduit set 608 that condensed maydrain to a sump collection port 656. The sump collection port 656 maydrain such condensate into the ground, in which case a plumbing drain“trap” is preferably included to retain a portion of the condensate in au-shaped segment that at least partially blocks the passage of gasses orliving creatures from the ground into the apparatus 600. Alternately thesump collection port 656 may be sealed off from the ground andaccumulate the condensate for pump-out through the primary entry port628 or the secondary entry port 632. When the sump collection port 656is sealed off from the ground in this fashion the apparatus 600illustrates a configuration having a drain (i.e., the sump collectionport 656) that is in flow communication with an air conduit (i.e., theconduit set 608), where the drain has at least one drain outlet forreceiving and expelling (for example, via pumping-out through theprimary entry port 628) to the outdoor atmosphere a substantial portionof any water vapor that condenses to a liquid water as the air and thewater vapor flow through the air conduit (i.e., the conduit set 608).The conduit set 608 is an example of a drainage pipe that is disposed ina substantially continuously-downward-sloping orientation where at leastone drain outlet (e.g., the sump collection port 656) is disposedproximal to an entry point (e.g., primary entry port 628) of an airconduit (e.g., the conduit set 608).

FIG. 15 also illustrates that the tank 612 has a domed bottom 660 formedconvex to an underground space. The domed bottom 660 may be shaped in asa cone or a pyramid. The domed bottom 660 may be provided for thepurpose of assisting in the flotation of air pockets up and away fromthe bottom of the tank 612 when it is installed in an underground space.Such air pockets would likely reduce the thermal conductivity betweenthe ground and the tank 612. Typically a tilt angle 666 of between aboutten degrees and 20 degrees is adequate for this purpose.

FIG. 16 illustrates how the apparatus 600 of FIGS. 14 and 15 may beintegrated with other devices for the purpose of heating and cooling aconditioned zone of a structure 700. The apparatus 600 is installed inthe ground 704 below a grade level 708. In the embodiment of FIG. 16 anintake system 712 inducts outside air and water vapor 716 and directs itto a first route 720 or to a second route 724 or to both the first route720 and the second route 724. Outside air and water vapor 716 that isdirected to the first route 720 passes through a transfer conduit 728 tothe entry port 628 of the apparatus 600. After flowing through theconduit set 608 (FIGS. 14 and 15) of the apparatus 600, conditioned air730 may be discharged through the exit port 636 of the apparatus 600into an energy recovery and ventilation unit 750. The energy recoveryand ventilation unit 750 generally incorporates an air mixing box andmay include air conditioning mechanisms such as dehumidifiers. Theenergy recovery and ventilation unit 750 may draw in outside air andwater vapor 716 through the second route 724, or the energy recovery andventilation unit 750 may draw conditioned air 730 from the apparatus600, or the energy recovery and ventilation unit 750 may draw in outsideair and water vapor 716 through the second route 724 and conditioned air730 from the apparatus 600. The choice is made by evaluating suchfactors a the temperature of the outside air and water vapor 716, thetemperature of the conditioned zone of the structure 700, and a user'spreference for providing regular fresh air. In the embodiment of FIG.16, the energy recovery and ventilation unit 750 is further configuredto optionally recirculate a portion of the conditioned air 730 backthrough the transfer conduit 728 to the apparatus 600.

Typically the energy recovery and ventilation unit 750 is configured todirect at least a portion of the conditioned air 730 into theconditioned zone of the structure 700. As shown in FIG. 16, a hot waterradiator 754 may be employed to heat the conditioned air 730 that isdirected into the conditioned zone of the structure 700 by the energyrecovery and ventilation unit 750. In the embodiment of FIG. 16, hotwater for the hot water radiator 754 is provided by a trombe (such as atrombe wall unit) that receives hot water circulated from a solar waterheater 762. In some embodiments the trombe is a stand-alone unit that isused to heat the conditioned zone of the structure 700 without passinghot water from the solar water heater 762 to a radiator (e.g., hot waterradiator 754), and in such stand-alone trombe embodiments the hot waterradiator 754 is not used.

In the embodiment of FIG. 16 the conditioned air 730 that is directedinto the conditioned zone of the structure 700 by the energy recoveryand ventilation unit 750 passes through a conventional HVAC system 766.The conventional HVAC system 766 may either heat or cool the conditionedair 730 that is directed into the conditioned zone of the structure 700by the energy recovery and ventilation unit 750. After passing throughthe conventional HVAC system 766 the conditioned air 730 that isdirected into the conditioned zone of the structure 700 by the energyrecovery and ventilation unit 750 is distributed to the conditioned zoneof the structure 700 by an air distribution system 770. One furtherfeature identified in FIG. 16 is a cleanout port 790 that is provided inthis embodiment to provide access to pump condensed water from theapparatus 600 or to provide access to the apparatus 600 for othermaintenance services.

Various methods may be use to install an apparatus for modifying anatmosphere for use in a conditioned zone of a structure. Most methodsbegin with a step of excavating a space underground below a grade level.The excavation site may be linked with either existing or newconstruction, and may, for example, be undertaken below a planned floorin a new construction or may be undertaken adjacent existingconstruction. The bottom surface of the excavation may be sloped to helpprovide a substantially continuously-downward-sloping orientation ofconduits in the apparatus. One embodiment proceeds with a step ofcasting a tank in-situ in the space. In this embodiment the tank istypically cast of concrete. The term “casting a tank” as used hereinrefers to a step where at least the bottom of the tank is cast, but thesides of the tank may be formed from blocks or other prefabricatedelements while still encompassing the intent of the term “casting atank.” The benefit of casting at least the bottom of the tank is thatgood thermal conductivity will be established between the ground and thetank if the concrete is poured directly onto (cast onto) the bottom ofthe excavated space. In this method, once the tank is cast in-situ, anair conduit system having an entry passage with an entry port and anexit passage with an exit port is disposed in the cast tank, such thatthe entry port and the exit port are above the grade level. A thermalballast material is then disposed in the tank. A further step isdisposing a lid on the tank, where the lid covers the tank and thethermal ballast material. The method generally concludes by backfillingto substantially the grade level the space underground that is notoccupied by the tank, the lid, the entry passage, and the exit passage,while providing for retention of the entry port and the exit port abovethe grade level.

Another method for forming an apparatus for modifying an atmosphere foruse in a conditioned zone of a structure also begins by excavating aspace underground below a grade level. This method then proceeds with astep of disposing a first thermal transfer material portion in thespace. The thermal transfer material is typically installed as a slurryor a sludge (such as concrete or mud), and it is provided for thepurpose of enhancing the thermal conductivity between a tank that willsubsequently be installed and the underground space. Once the thermaltransfer material is installed a tank having a bottom and sides isinstalled in the space, where the bottom of the tank rests on thethermal transfer material. The method further includes a step ofdisposing in the tank an air conduit system having an entry passage withan entry port and an exit passage with an exit port, where the entryport and the exit port are above the grade level. The method alsoincludes a step of disposing a thermal ballast material in the tank. Thethermal ballast material adds weight to sink the tank into the slurry orsludge and provide good thermal contact between the tank and the thermaltransfer material. A lid is disposed on the tank, where the lid coversthe tank and the thermal ballast material. In this method a secondportion of thermal transfer material is disposed in the space adjacentthe sides of the tank. The method generally concludes with backfillingto substantially the grade level the space underground that is notoccupied by the tank, the lid, the entry passage, the exit passage, andthe thermal transfer material, while providing for retention of theentry port and the exit port above the grade level.

Various methods may be used to modify an atmosphere for use in aconditioned zone of a structure. For example, a method may involveestablishing a cycle of transitions between on and off phases of flow ofoutside air through an underground air conduit to reformulate theoutside air as conditioned air for use in the conditioned zone of thestructure. The off phase may be monitored for a likelihood of anundesirable characteristic of the conditioned air in the air conduit.Monitoring may include sensor measurements or time durationmeasurements. The undesirable condition may be excessively hightemperature, or the undesirable condition may be stale air that has beensubstantially dormant for an extended period of time, and may havepicked up off-gasses from the underground air conduit. Prior to thetransition from an off phase of flow to an on phase of flow, theconditioned air in the air conduit may be discharged to an outsideatmosphere if the likelihood of the undesirable characteristic exceeds athreshold value. The term “outside atmosphere” refers to the ambient airatmosphere outside the conditioned zone of the structure. For example,the time duration of the off phase may be monitored and if the timeduration exceeds a limit value (perhaps exceeding about five minutes)the air in the air conduit may be discharged to the outside atmospherebefore starting the cycle for flowing outside air through theunderground air conduit to the conditioned zone of the structure.Alternately or in addition, the temperature of the conditioned air inthe underground air conduit may be monitored and if it exceeds athreshold value (such as about 80° F. (about) the conditioned air in theunderground air conduit may be discharged to the outside atmospherebefore starting the cycle for flowing outside air through theunderground air conduit to the conditioned zone of the structure.

Example

FIG. 17 illustrates experimental results from an apparatus for modifyingan atmosphere for use in a conditioned zone of a structure that wasinstalled for test and evaluation purposes. The system was built andsituated under a driveway in preparation for a future building. FIG. 18shows its basic construction. This system was constructed as two layersof piping as shown and is arranged based upon 4.0″ diameter inlet andoutlet pipes. The primary heat exchange pipes are 3.0 inch diameter. Toensure good ground contact, the piping system was buried in low gradeconcrete, which also serves to physically protect the system. Expandedpolystyrene geofoam provided an additional thermal barrier over theconcrete to minimize thermal transport to and from the surface. Testingof the system is accomplished utilizing an air fan assembly to draw airthrough the piping assembly. A temperature sensor was placed at the airinlet. A similar sensor was placed at the air outlet. Both temperatureswere plotted continuously, one example of which is shown in FIG. 17. Airflow through the system was approximately 200 cubic feet per minute(about 5,670 liters per minute). Testing of the system did not require abuilding placed on the system. Having a building might actually be acomplicating factor because the building construction parameters mightthen influence performance measurements. In the two day periodillustrated in FIG. 17, the temperature of outdoor air admitted to thetest system through its inlet (entry port) varied from just above 55° F.(about 12.8° C.) to almost 100° F. (about 37.8° C.). However theapparatus for modifying an atmosphere for use in a conditioned zone of astructure provided air at an outlet (exit port) temperature that variedonly between about 67° F. (about 19.4° C.) and 73° F. (about 22.8° C.).Unexpectedly little condensation of water vapor occurred in the testsystem over several months of operation.

The foregoing descriptions of embodiments have been presented forpurposes of illustration and exposition. They are not intended to beexhaustive or to limit the embodiments to the precise forms disclosed.Obvious modifications or variations are possible in light of the aboveteachings. The embodiments are chosen and described in an effort toprovide the best illustrations of principles and practical applications,and to thereby enable one of ordinary skill in the art to utilize thevarious embodiments as described and with various modifications as aresuited to the particular use contemplated. All such modifications andvariations are within the scope of the appended claims when interpretedin accordance with the breadth to which they are fairly, legally, andequitably entitled.

1. An apparatus for modifying an atmosphere for use in a conditionedzone of a structure, comprising: a tank for containing a thermal ballastmaterial in an underground space below a grade level; and an air conduitsystem disposed within the tank for contacting the thermal ballastmaterial, the air conduit system having an entry passage with an entryport for an air flow connection with the conditioned zone of thestructure and an exit passage with an exit port for the air flowconnection with the conditioned zone of the structure.
 2. The apparatusof claim 1 wherein the air conduit system comprises a conduit having aserpentine path.
 3. The apparatus of claim 1 wherein the air conduitsystem comprises a plurality of conduits following substantiallyparallel serpentine paths.
 4. The apparatus of claim 1 wherein the tankhas a lid and the apparatus further comprises insulative foam disposedabove the lid and below the grade level.
 5. The apparatus of claim 1wherein the tank has a domed bottom formed convex toward the undergroundspace.
 6. A method for forming an apparatus for modifying an atmospherefor use in a conditioned zone of a structure, comprising: (a) excavatinga space underground below a grade level; (b) casting a tank in-situ inthe space; (c) disposing in the tank an air conduit system having anentry passage with an entry port and an exit passage with an exit port,wherein the entry port and the exit port are above the grade level; (d)disposing a thermal ballast material in the tank; (e) disposing a lid onthe tank, the lid covering the tank and the thermal ballast material (f)backfilling to substantially the grade level the space underground thatis not occupied by the tank, the lid, the entry passage, and the exitpassage, while providing for retention of the entry port and the exitport above the grade level.
 7. The method of claim 6 wherein step (e)further comprises disposing a foam insulation above the lid on the tankbelow the grade level, and wherein step (f) comprises backfilling tosubstantially the grade level the space underground that is not occupiedby the tank, the lid, the foam insulation, the entry passage, and theexit passage, while providing for retention of the entry port and theexit port above the grade level.
 8. A method for forming an apparatusfor modifying an atmosphere for use in a conditioned zone of astructure, comprising: (a) excavating a space underground below a gradelevel; (b) disposing a first thermal transfer material portion in thespace; (c) disposing a tank having a bottom and sides in the space,where the bottom of the tank rests on the thermal transfer material; (g)disposing in the tank an air conduit system having an entry passage withan entry port and an exit passage with an exit port, wherein the entryport and the exit port are above the grade level; (h) disposing athermal ballast material in the tank; (i) disposing a lid on the tank,the lid covering the tank and the thermal ballast material; (j)disposing a second thermal transfer material portion in the spaceadjacent the sides of the tank; (k) backfilling to substantially thegrade level the space underground that is not occupied by the tank, thelid, the entry passage, the exit passage, and the thermal transfermaterial, while providing for retention of the entry port and the exitport above the grade level.
 9. The method of claim 8 wherein step (i)further comprises disposing a foam insulation above the lid on the tankbelow the grade level, and wherein step (k) comprises backfilling tosubstantially the grade level the space underground that is not occupiedby the tank, the lid, the foam insulation, the entry passage, the exitpassage, and the thermal transfer material, while providing forretention of the entry port and the exit port above the grade level. 10.A method for modifying an atmosphere for use in a conditioned zone of astructure, comprising: (a) establishing a cycle of transitions betweenon and off phases of flow outside air through an underground air conduitto reformulate the outside air as conditioned air for use in theconditioned zone of the structure; (b) monitoring the off phase for alikelihood of an undesirable characteristic of the conditioned air inthe air conduit; (c) prior to the transition from an off phase of flowto an on phase of flow, discharging the conditioned air in the airconduit to an outside atmosphere if the likelihood of the undesirablecharacteristic exceeds a threshold value.
 11. The method of claim 10wherein step (b) comprises monitoring a time duration of the off phaseand wherein the threshold value of step (c) comprises an elapsed timeinterval.
 12. The method of claim 10 wherein step (b) comprisesmonitoring a temperature of the conditioned air in the air conduit andwherein the threshold value of step (c) comprises a maximum temperature.13. An apparatus for modifying an atmosphere for use in a conditionedzone of a structure, comprising: an air conduit having a length andbeing disposed at least partially in a stable temperature environment,wherein the air conduit has an entry port that is open to an outdooratmosphere that is external to the conditioned zone of the structure; anair movement system for conveying a flow of air and water vapor from theentry port through the air conduit and out an exit port in the airconduit into the conditioned zone of the structure; and at least onedrain that is in flow communication with the air conduit, the drainhaving at least one drain outlet for receiving and expelling to theoutdoor atmosphere that is external to conditioned zone of the structurea substantial portion of any water vapor that condenses to a liquidwater as the air and the water vapor flow through the air conduit;wherein the apparatus is further configured such that substantially allof the air and water vapor that flows through the apparatus travels adistance that is substantially equal to the length of the air conduit.14. The apparatus of claim 10 wherein the at least one drain comprises adrainage pipe that has a length that is substantially the same length asthe length of the air conduit and that is disposed in a substantiallycontinuously-downward-sloping orientation.
 15. The apparatus of claim 10wherein the at least one drain comprises a drainage pipe that isdisposed in a substantially continuously-downward-sloping orientationand the at least one drain outlet is disposed proximal to the entrypoint or proximal to the entry port of the air conduit.
 16. Theapparatus of claim 10 wherein the air conduit is disposed in asubstantially continuously-downward-sloping orientation from the exitport to the entry port and the drain comprises a trough portion of theair conduit and the entry port comprises the at least one drain outlet.17. The apparatus of claim 10 wherein the air conduit is disposed in asubstantially continuously-downward-sloping orientation and the at leastone drain comprises a trough portion of the air conduit and the at leastone drain outlet comprises a drain hole in the trough portion.
 18. Asystem for conditioning air in a conditioned zone of a structure,comprising: a source of air external to the conditioned zone; aregulator configured to provide a regulated flow rate of external airfrom the source of external air; an air conduit system disposed at leastpartially in a stable temperature environment and having a first entryport that is in fluid communication with the air in the conditioned zoneof the structure, and having a second entry port that is in fluidcommunication with the regulated flow rate of external air, and havingan exit port into the conditioned zone of the structure; and a source ofpressure differential that flows air into the air conduit system fromthe first entry port and from the second entry port of the air conduitsystem and through a substantial portion of the air conduit system andout of the exit port of the air conduit system into the conditioned zoneof the structure.
 19. An apparatus for modifying an atmosphere for usein a conditioned zone of a structure, comprising a plurality of flowreversion blocks interconnected by air conduit, each block having aplurality of openings in only one face, wherein air enters the blockthrough one or more openings in the face and exits the block through oneor more openings the face.